1. Field of Invention
The present invention relates to earth augers and more particularly to the provision of an adapter plate for supporting cutting teeth disposed at the leading edge of the auger flight in order rapidly to adapt the auger for a most efficient operation under differing subsurface conditions.
2. The Prior Art
Earth augers for making hole in the earth whether it be unconsolidated or rock formations are well known as exemplified by U.S. Pat. No. 2,578,014. This patent describes an auger system having a central stem and a pair of helically shaped blades secured to the stem one on each side thereof and opposite one another. The blades form a double helix. Plates are secured to the leading edges of the blades with cutters radially spaced one from the other mounted to the plates.
U.S. Pat. No. 2,731,237 describes an earth auger having a plurality of peripherally spaced cutting bits mounted along the periphery of the lower portion of a flight in spaced relationship one from the other to cut annular zones of increasing diameter as the auger progresses into the earth.
The efficiency of making hole can be improved by arranging the cutting bits or teeth not only in step fashion as above described but also as shown in U.S. Pat. No. 3,794,129 in radial relationship one to the other so that an overlapping cutting action takes place. But this patent like the preceding patent provides for the mounting of the cutting teeth directly on the leading edge of the flight and thus the bit or tooth holders are a permanent part of the auger system.